Lithographic plate graining machine



Awal 21, ma, R. FRI'TSCHE 2,@3852 LITHOGRAPHIC PLATE GRAINING MACHINElFiled April 22, 1935 2 Sheets-Sheet 1 INVENTOR Rudolf FT'L'SCZQATTORNEYS Patented Apr. 21, 1936 UNITED STATES PATENT OFFICELITHOGRAPHIC PLATE GRAINING MACHINE 7 Claims.

This invention relates to graining plates for lithographing use,anobject being to provide a construction wherein the plate may be grainedcomparatively quickly and with comparatively little noise.

Another object of the invention is to provide a Vgraining machine forlithographie plates wherein means are provided for producing a grainingaction whereby a very fine grain is secured or a coarser grain accordingto the way the parts are actuated.

A further object more specifically is to provide a graining machinewherein the tank or box is given a gyratory movement through a power`driven means and through the use yof spring-held supporting standards.

An additional .object of the .invention is to provide a graining machinewherein there is a gyrating box for receiving the plates to be ground,and a cover for the box formed to substantially eliminate the noisecreated during the graining operation.

In the accompanying drawings- Figure 1 is a top plan view of a grainingmachine disclosing an embodiment of the invention;

Fig. 2 is a section view through Fig. 1 on approximately the line 2 2;

Fig. Sis a bottom plan View of Y a pulley wheel and counterweightdisclosing ,certain features of the invention;

Fig. 4 is a sectional view through Fig. 3, approximately on the line4.-.-4.

Referring to the accompanying drawings by numerals, I indicates a tankor box which has a bottom 2 and suitable side members 3. This tank orbox. is supported by Vany desired number of standards 4, there beingpreferably four, as indicated in dotted lines in Fig. 1. These standardsare preferably arranged at the extreme outer portions of the cornersofthe box and act to normally support the box in such a way -that thestandards will be vertical, but when electricmotor or other primemoveris vfunctioning and also the other parts are functioning the standardswill swing back and forth in an oscillatingv way vto permit a gyrationof the box I. As therespective standards 4 are identical and theassociated parts also are identical, a description of one will apply toall.

As illustrated -particularly to Fig. 2, the standard 4 is connected by asuitable socket tting rI5 to a plate 1. The socket fitting 6 may bewelded or otherwise secured to plate l, which plate hasan inverted cup 8arranged opposite the cup 9 .of a plate -I Il. There are provided anydesired number of rods -II having the lower end screwed into plate I0,said rods extending loosely through suitable apertures I2 in plate l.'Ihere a-re provided for each rod II, a spring I3 between plates 'I andIB, and ya spring I4 above plate 'I, spring I4 being normally held undertension by a nut I5. As a matter of fact, both of the springs of eachrod are held under tension by the respective nuts I5, land this tensionis Wholly sufficient to hold the standard 4 upright when the device isnot operating. As indicated in dotted lines: in Fig. 1, there are ,eightrods I I kbut a greater or less number could be used without departingfrom the invention. It will also be noted that a thrust ball or bearingI6 is accommodated in the cups 8 and 9. Both ends of each standard 4 areformed with the structure just described so that it is thought nofurther description is needed for the upper part of the rods the upperand lower ends are identical, each having a thrust ball I6, plates I andI0, and rods and springs as just described. In case the oscillation orgyration of the box I should be too great, the same may be varied indiierent manners, as, for instance, by shifting a counterweight I'I,hereinafter fully described, or by Varying the tension of the springs I3and I4.

Arranged beneath the tank or box I, is a large pulley kwheel I8,carrying the counterweight. From Figs. 3 and 4 it will be observed thatthe counterweight I'I is slidingly mounted on rods I9 Vand 20, and has athreaded member 2l threaded therein, said threaded member being mountediti the respective parts of the pulley wheel I8, as shown in Fig. 4. Thecounterweight I'I, as far as the threaded member 2| is concerned, actsas a traveling nut so that when the threaded member l2I is operated byan instrument engaging the head 22, the counterweight will be movedradially inwardly or outwardly in respect to the wheel I8. The pulleyWheel I8 has a shaft 23 keyed or otherwise rigidly secured thereto, oneend of the shaft being loosely journaled in a socket 24 welded orotherwise secured to the bottom 2 of the tank I. The lower end of theshaft 23 is loosely mounted in a socket 25, said socket being mounted onone or more cross bars 26, said cross bars at the ends Ybeing secured bybolts or otherwise to the bottom of the box I.

It will be noted that the bottom of the box I has one or morebeams 21connected to the bottom I and the member 26 is secured by bolts orscrews 28 thereto. 'Ihe detail construction of the bottom part ofthe boxI maybe varied without departing ffromthe spirit of the invention sothat one or more beams 2'I may be provided in order to stiifen or bracethe box.

A belt 29 is adapted to fit around the wheel I8 and then pass overguiding pulleys 30 and 3| to guide the belt so that it will then passover the driving pulley 32, which driving pulley is rigidly secured tothe rotating part of the prime mover 5. It will, therefore, be observedthat when the prime mover 5 is moving the belt 29, the pulley wheel I8will be rotated and will naturally move the counterweight I1. Thiscounterweight will move comparatively fast and will, in a certain sense,throw or urge the parts by reason of centrifugal action so as to give anoscillating, or rather gyrating, movement to the box I. This gyratingmovement may be increased in amplitude or decreased by moving thecounterweight II inwardly or outwardly with respect to the pulley wheelI8. When the counterweight II is at its outermost point, there will bethe greatest movement or gyration of b ox I. This usually results inproviding coarser graining, as well as faster graining. By moving thecounterweight I'I inwardly, the gyration is reduced in amplitude and thegraining becomes ner and finer.

In using a graining machine of the type just described, or any typewhich is now in common use, there is usually placed in the box a numberof plates 33 to be grained. These plates are stacked and extend almostfrom one end to the other of the box, and also from one side to theother. Water is placed in the box until these plates are whollysubmerged and a thin layer of sand is placed on top of the uppermostplate, and finally the various balls 34 are placed substantiallyas shownin Fig. 2. The balls are usually less than half submerged, while thesand is usually completely submerged in water. These balls may beordinary marbles, steel balls, or any other small round objects havingsome appreciable weight. During the gyration of the device these ballswill naturally move and cause the sand to produce the desired grainingaction in the presence of water.

During this movement noise is produced which is more or lessobjectionable. 'I'o obviate this noise there has been provided a cover35, which cover is preferably divided into two parts, as shown in Fig.1, said parts being connected together by hinges 36. These parts areformed identical and when in position snugly fit the box I, but may bereadily removed therefrom completely, or only one part may be swung outof the way when temporary access is desired to the interior of the box.As illustrated, there are provided transverse bars of wood or otherdesired material, 38, 39, 40 and 4I, said bars overlapping the sideedges of the box I. In addition, connecting bars 42 and 43 are providedfor the part or section 35', while connecting bars 44 and 45 areprovided for the part or section 35". This framework just described ispreferably formed from wood, and arranged between the upper and lowerparts of this framework is positioned for each of the sections 35 and35", a plate 46, which may be of beaver board or similar material, andarranged at the top and bottom of the respective parts of the cover aresimilar beaver board cover plates 4'I and 48, which, in turn, arepreferably covered with thin metal sheets 49 and 50. This leaves a spacewhich is preferably iilled with some sort of waste 5I and 52, said wastebeing wool, cotton, or other material whereby a substantiallysound-proof structure is presented.

a,oes,352

When the parts are in the position shown in Fig. 2 the machine is readyfor use, and after the machine has run for a certain length of time, as,for instance, a half hour more or less, the top plate of the pile ofplates 33 will have been properly grained. The entire cover 35 may thenbe removed, or, if desired, only one part, as, for instance, section35", may be swung back over the other part and then the uppermost plateslid out. This will allow the balls and sand to drop down onto the nextlower plate. After the second plate has been grained, it is removed in alike manner until all the plates have been grained. If desired, watermay be added vfrom time to time, or removed from time to time, and alsosand may be added or removed as desired.

The cover 35 is adapted to t rather snugly the side walls 3 of the boxI, so as to prevent the escape of sound from inside the box.

Preferably at each corner of the tank there is arrangedaJ clampingmember 53, each of which members is provided with a set screw and ahinged connection with the side walls 3. These clamping members aredesigned to hold the various plates 33 against shifting when the deviceis operating. After the top plate has been grained these clampingmembers must be swung out of the way before the top plate can beremoved, and then they are swung back and the set screw again caused tofunction.

I claim:

1. A graining machine of the character described, comprising a boxadapted to receive plates to be grained, means for moving said box sothat a graining action may take place, and a substantially sound-proofcover for said box formed with a portion tting within the box and vithextending members resting on top of the 2. A graining machine, includinga box, a plurality of supports for said box, said supports beingswingable in all directions, and means for noving said box to give agyratory motion there- 3. A graining machine, including a box, aplurality of supports therefor, a plurality of springs connecting saidbox with said supports whereby the springs will act to normally tend tohold the box in a position for holding the supports vertically, saidsprings acting to return the supports to a vertical position when movedtherefrom, and a power-driven counterweighted wheel connected with thebox for giving the box a gyratory movement.

4. In a graining machine of the character described, a box, and aplurality of supports therefor, each of said supports comprising astandard, a bearing member at each end of the standard, a plate securedto said standard at each end thereof, a plurality of rods xed at oneend, and extending loosely through each of said plates, and a spring oneach side of each of said plates surrounding the respective rods andacting to hold said supports in a substantially vertical position butpermitting a movement from the vertical position.

5. In a graining machine of the character described, a box, and aplurality of supports therefor, each of said supports having at each enda xed plate, a bolt mounted on said xed plate, a second plate rigidlysecured to the support and spaced from the iixed plate, said secondplate having a plurality of apertures adjacent the periphery, a rodextending loosely through each of said apertures, each of said rodsbeing at one end screwed into said xed plate, an adjusting nut at theopposite end of each of said rods, and a plurality of coil springssurrounding each of said rods, there being a coil spring on each side ofsaid second plate and acting on said second plate to normally hold thesame substantially parallel with the xed plate, said nuts acting to varythe tension of said springs so as to resist movement of the support fromthe vertical and to return the supports to a vertical position whenpermitted.

6. A graining machine of the character described, including a boxadapted to receive the material to be grained, swingable supports forsaid box, a wheel rotatably mounted on the lower part of said box, acounterweight radially movably mounted on said Wheel, means for lockingsaid counterweight at different distances from the center of said wheel,and a driving belt engaging said wheel for rotating the same.

'7. A graining machine of the character described, including a box, apulley arranged on the under surface of the box, a journal pin for saidpulley carried by said box, means for driving said pulley, and acounterbalancing structure for said pulley, said counterbalancingstructure including a weight movable radially with respect to the centerof the pulley, and means for moving and holding in different positionssaid weight, whereby the action of the pulley in gyrating said box willbe varied.

RUDOLF FRITSCI-IE.

